Flexible substrate with integrated circuit

ABSTRACT

In one example, a flexible circuit for a fluid cartridge includes a single flexible substrate, an integrated circuit connected to the single flexible substrate, and an electrical connector pad array arranged in a constant pattern on the single flexible substrate for connection to a host controller. The electrical connector pad array includes first electrical connector pads connected to the integrated circuit and second electrical connector pads for connection to a fluid dispensing die.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 14/863,902, filed Sep. 24, 2015, which is a continuation of U.S.application Ser. No. 14/375,856, filed Jul. 31, 2014 (now U.S. Pat. No.9,162,469), which is itself a 35 U.S.C. 371 national stage filing ofInternational Application serial no. PCT/US2012/035889, filed Apr. 30,2012, each of which are incorporated by reference herein in theirentireties.

BACKGROUND

Examples of fluid cartridges are ink cartridges provided with integratedfluid dispensing dies. The fluid dispensing dies are provided withnozzles and actuators. The actuators can be signaled for fluiddispensing through a control circuit in a host device. When thecartridge is installed in the printer, the electrical connector padarray is connected to corresponding connector pads of the printer, sothat a printer controller can signal the die circuit and the actuators,and fluid can be dispensed on a medium in accordance with input digitalimage data. The electrical connector pad array and the fluid dispensingdie are attached to a flexible circuit. In industry, such flexiblecircuit can also be referred to as tab flex, or tab head assembly. Theflexible circuit oftentimes consists of a flexible film, a window forthe fluid dispensing die, the fluid dispensing die, electrical connectorpads, and conductor lines connecting the connector pads to theactuators. It can be challenging to integrate further functionalitieswith the flexible circuit in a cost efficient manner.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustration, certain examples constructed inaccordance with the teachings of this disclosure will now be describedwith reference to the accompanying drawings, in which:

FIG. 1 illustrates a diagram of an example of a flexible circuit;

FIG. 2 illustrates a diagram of an example of a cross sectional sideview of a fluid cartridge;

FIG. 3 illustrates a diagram of a front view of the example of the fluidcartridge of FIG. 2;

FIG. 4 illustrates a diagram of top view of another example of aflexible circuit;

FIG. 5 illustrates a diagram of an example of a cross sectional sideview of the flexible circuit of FIG. 4;

FIG. 6 illustrates a diagram of a portion of the example of the flexiblecircuit of FIG. 4;

FIG. 7 illustrates a block diagram of an example of a securemicrocontroller;

FIG. 8 illustrates a flow chart of an example of a method ofmanufacturing a flexible circuit;

FIG. 9 illustrates a flow chart of another example of a method ofmanufacturing a flexible circuit; and

FIG. 10 illustrates a flow chart of a part of a further example of amethod of manufacturing a flexible circuit.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings. The examples in the description and drawingsshould be considered illustrative and are not to be considered aslimiting to the specific example or element described. Multiple examplesmay be derived from the following description and/or drawings throughmodification, combination or variation of certain elements. Furthermore,it may be understood that examples or elements that are not literallydescribed may be derived from the description and drawings by a personof ordinary skill in the art.

FIG. 1 illustrates a diagram of an example of a flexible circuit 1. Forexample the flexible circuit 1 is arranged to be applied to a fluidcartridge 80 (FIG. 2, 3). For example, the flexible substrate 2 consistsof a single integrated substrate, for example a single flexible film.For example, the flexible substrate 2 is cut out of a single continuousflexible film. The flexible circuit 1 further includes a firstintegrated circuit 3 attached to the flexible substrate 2. For example,the first integrated circuit 3 includes a memory 4 and a processing unit5. The flexible circuit 1 includes an electrical connector pad array 6arranged to receive signals from a host device, such as for example aprinter or other fluid dispensing device. For example, other devicessuch as web servers or mobile communication devices can communicate withthe first integrated circuit 3 through the printer or directly.

The example electrical connector pad array 6 is arranged in a constantpattern. For example, the electrical connector pad array 6 includes anumber of connector pads regularly deposited on the flexible substrate 2along parallel lines, as illustrated in FIG. 1. For example theelectrical connector pad array 6 is equal or similar to a conventionalelectrical connector pad array 6, for example as known from existingfluid cartridge connector pad arrays. The electrical connector pad array6 includes first electrical connector pads 7 connected to the firstintegrated circuit 3 and second electrical connector pads 8 forconnection to a fluid dispensing die 9. For example, the firstelectrical connector pads 7 are connected to first conductor lines 10that are connected to the first integrated circuit 3. For example, thesecond electrical connector pads 8 are connected to second conductorlines 11 for connection to the fluid dispensing die 9. For example, bondpads connect the first and second conductor lines 10, 11 to the firstintegrated circuit 3 and the fluid dispensing die 9, respectively. In anexample, the bond pads are conductive joints that can be connected torespective leads through gang bonding or other bonding techniques. Forexample, separate joints are formed on the bond pads or connector pads7, 8, or the bond pads or connector pads 7, 8 act as joints.

For example, the fluid dispensing die 9 includes at least one ofactuators, nozzles, slots and a second integrated circuit. The secondelectrical connector pads 8 are connected to at least one of theseactuators, nozzles, slots, and second integrated circuit through thesecond conductor lines 11.

In an example, the flexible circuit 1 of FIG. 1 allows for gang bondingof the features on the flexible substrate 2. For example, the electricalconnector pads 7, 8 and the conductor lines 10, 11 are connected by gangbonding. For example, the first integrated circuit 3 and the fluiddispensing die 9 are connected to the corresponding conductor lines 10,11, respectively, by gang bonding. For example, the integrate circuit 3can be gang bonded to the flexible substrate 2 with the same gangbonding tool, on the same gang bond table, and in the same gang bondingprocess step as the electrical connector pad array 6 and die 9, to allowfor manufacturing with relatively cost efficient tools and processes.

FIGS. 2 and 3 illustrate a diagram of a cross sectional side view and afront view, respectively, of a fluid cartridge 80. FIG. 2 represents across sectional side view of FIG. 3. The dimensions in FIGS. 2 and 3 arestrongly exaggerated for reasons illustration. The fluid cartridge 80 ofFIGS. 2 and 3 includes a housing 23 and the flexible circuit 1 attachedto the housing 23. In FIGS. 2 and 3 the flexible circuit 1 is mounted tothe cartridge 80 but it should be understood that in an example theflexible circuit 1 is a product in itself, for example an intermediaryproduct, separate from the fluid cartridge 80. The housing 23 includes afluid reservoir 12. For example, the housing 23 includes a single castmold and a lid or shell for tapping or closing the reservoir 12. Theflexible circuit 1 includes the flexible substrate 2 and connected to itthe first integrated circuit 3 and the fluid dispensing die 9. Forexample, the fluid cartridge 80 (FIG. 2, 3) is an ink cartridge withintegrated printhead. For example, the fluid dispensing die 9 is aprinthead die. For example, the actuators are at least one of thermaland piezo resistors for jetting ink.

The illustrated example of FIGS. 2 and 3 includes a single chamberreservoir 12. In another example, the fluid cartridge 80 includesmultiple reservoir chambers for different fluids, for example differentcolors of ink, separated by inner walls. For example at least onecapillary medium 15 and at least one standpipe 16 are provided in thereservoir 12, for example one capillary medium 15 and standpipe 16 perchamber, for providing the fluid to the fluid dispensing die 9. In theillustrated example, the fluid cartridge 80 includes a bed 22 or framethat can be pre-molded in the housing 23, for receiving and connectingthe fluid dispensing die 9 to the housing 23. In an example, the fluiddispensing die 9 is connected with the flexible substrate 2 before beingattached to the housing 23.

The fluid dispensing die 9 includes nozzles 13 and actuators 14. Forexample, the actuators 14 include thermal or piezo resistors forejecting fluid from chambers. A second integrated circuit 17 is providedthat is connected to, for example included in, the fluid dispensing die9. In an example the second integrated circuit 17 includes a secondmemory 18. In an example, the second integrated circuit 17 includes atleast one transistor 20, for example to facilitate triggering of theactuators 14. For example, the fluid dispensing die 9 includes conductorcircuits 21 for connecting the different circuits. For example, theconductor circuits 21 connect the actuators 14 to the second integratedcircuit 17 and to the electrical connector pad array 6, for example tofacilitate triggering of the actuators 14 by a host device controller.In the illustrated example, the second integrated circuit 17 is arrangedat a distance from the first integrated circuit 3. For example, thesecond integrated circuit 17 is arranged in or near the fluid dispensingdie 9, near a bottom 25 of the fluid cartridge 80, and the firstintegrated circuit 3 is arranged near the electrical connector pad array6, for example at a front 26 of the fluid cartridge 80. For example thesecond integrated circuit 17 is integrated with the fluid dispensing die9. For example, the second integrated circuit 17 is fabricated in JetMosIntegrated Circuit fabrication processes, wherein also the die 9including the transistors 20 and the memory 18 can be fabricated. Forexample, the memory 18 includes at least one of a Read Only Memory(ROM), a series of links, and an Erasable Programmable Read-Only Memory(EPROM), for example having a limited memory of approximately 200 bitsor less, or of approximately 400 bits or less, or of approximately 2048bits or less, or more.

For example, a cartridge ID 28 is stored on the memory 18 of the secondintegrated circuit 17. For example, the cartridge ID 28 includes a partof a unique serial number pertaining to the cartridge 80. For example,the cartridge ID 28 includes a code that corresponds to a further IDsuch as the serial number. For example the cartridge ID 28 includes ahash, an encrypted code or an obfuscated version of a further ID such asthe serial number. For example, the cartridge ID 28 stored on the secondintegrated circuit 17 is secured using an industry standard securitycoding method. For example, the host device controller is configured todecode or otherwise process the cartridge ID 28 for verification.

For example, an authentication code 29 is stored on the memory 4 of thefirst integrated circuit 3. For example, the authentication code 29corresponds to said cartridge ID 28 stored on the second integratedcircuit 17, so that the ID stored on the second integrated circuit 17and the authentication code 29 stored on the first integrated circuit 3can be matched, for example by a host device controller. In one example,the cartridge ID 28 and the authentication code 29 are equal and can bedirectly matched. In another example, one or both of the cartridge ID 28and the authentication code 29 needs to be processed before being ableto match the cartridge ID 28 and the authentication code 29. Forexample, the authentication code 29 is secured, for example encrypted.For example the authentication code 29 is a secret key. For example, theauthentication code 29 includes a hash, an encrypted code or anobfuscated version of the cartridge ID 28 or of a further ID such as theserial number, so as to allow for said matching. For example, the hostdevice controller is configured to decode or otherwise process theauthentication code 29 for matching with the cartridge ID 28. Insteadof, or in addition to the authentication code, the first integratedcircuit 3 can container a further secret key for authentication.

In an example, the second integrated circuit 9 includes a hash of thecartridge ID 28. For example, the first integrated circuit 3 includes ahash of the authentication code 29. For example, a cryptographicallysignature is applied over one or both of the hashes with an asymmetricalgorithm, for example using a private key. For example the private keyis arranged according to at least one these techniques: RSA (Rivest,Shamir, Adleman), ECDSA (Elliptic Curve Digital Signature Algorithm) andDSA (Digital Signature Algorithm). For example, the signature is storedin a tamper resistant memory, for example on the memory of the firstintegrated circuit 3. For example a host device can validate anauthenticity of the cartridge 80 by reading the digital signature, thecartridge ID 28 and the authentication code 29, and validate them usinga public key which is already known to the host device.

As can be seen from FIGS. 2 and 3, in an example the first and secondelectrical connector pads 7, 8 form part of a single regularly patternedconnector pad array 6. For example, the first and the second electricalconnector pads 7, 8 are arranged long straight, parallel lines 27, forexample in rows or columns. In an example that is not shown the lines 27have an inclined orientation with respect to longitudinal edges of theflexible substrate 2. First and second electrical connector pads 7, 8can be arranged along the same line 27. In the illustrated example, theelectrical connector pad array 6 includes two parallel lines 27 ofelectrical connector pads 7, 8, each line including both first andsecond electrical connector pads 7, 8. One example of the flexiblecircuit 1 includes at least four first electrical connector pads 7 thatare regularly arranged in the electrical connector pad array 6 that areconnected to the first integrated circuit 3, for example including aground connection, a power supply connection (Vcc), a data connection,and a clock circuit connection.

For example, the first integrated circuit 3 and the second integratedcircuit 17 share at least one combination connector pad A, B. In thisdisclosure the combination connector pad A, B can be defined as acombination of both a first and a second electrical connector pad 7, 8.The combination connector pads A, B are electrically connected to thefirst and second conductor lines 10, 11. For example at least onecombination connector pad A, B is configured to function as a ground forthe first and second integrated circuit 3, 17, when connected to a hostdevice. For example at least one combination connector pad A, B isconfigured to function as a power supply (Vcc) for the first and secondintegrated circuit 3, 17, when connected to the host device.

For example, having a constant pattern of electrical connector pads 7, 8can allow for relatively cost efficient manufacturing of the flexiblecircuit 1, as well as the corresponding host device connectors. In anexample, applying the first integrated circuit 3 to the flexible circuit1 requires no modification, or only little modification, to existingflexible circuit fabrication.

FIGS. 4 and 5 illustrate a further example of a flexible circuit 1. Theexample flexible circuit 1 includes the fluid dispensing die 9. Theexample flexible circuit 1 includes the flexible substrate 2 and thefirst integrated circuit 3. The flexible substrate 2 includes a tape orfilm and flexible conductor lines 10, 11. For example, the flexiblesubstrate 2 is made of strong polymer thin film material such aspolyimide. The thin conductor lines 10, 11 are for example imaged byphotolithography. In an example, the single flexible substrate 2comprises at least one first window 30 and at least one second window31. For example the first integrated circuit 3 is connected to theflexible substrate 2 near edges of the first window 30. For example, thefluid dispensing die 9 is connected to the flexible substrate 2 nearedges of the second window 31 via bond pads and/or further joints. Forexample, the fluid dispensing die 9 and/or the first integrated circuit3 are gang bonded or wire bonded to the flexible substrate 2 via bondpads. For example, the integrated circuit 3 is gang bonded to the firstconductor lines 10, via first bond pads, and the fluid dispensing die 9is gang bonded to the second conductor lines 11, via second bond pads.For example, the first integrated circuit 3 and the fluid dispensing die9 are connected to the same side of the flexible substrate 2. Forexample the first integrated circuit 3 and the fluid dispensing die 9are gang bonded on the same gang bond table, in one process step. Inanother example, the fluid dispensing die 9 and the first integratedcircuit 3 are bonded in separate process steps wherein for example theflexible substrate 2 is repositioned or moved to another tool betweenthese process steps.

For example, an encapsulation layer 32 encapsulates the first integratedcircuit 3. For example, an encapsulation layer 33 encapsulates theelectrical connector pad array 6. The illustrated example encapsulationlayer 33 of the electrical connector pad array 6 also covers the firstintegrated circuit 3. The example encapsulation layer 33 illustrateddefines one continuous encapsulation layer 33 for the connector padarray 6 and the first integrated circuit 3. In another example, multipleencapsulation islands 32 could be applied for encapsulating the firstintegrated circuit 3 and the electrical connector pad array 6separately. For example, the encapsulation layers 32, 33 are made of thesame material and applied to the same side of the flexible substrate 2.For example, the encapsulation layers 32, 33 are provided in the samemanufacturing process step. For example, the encapsulation layer 32, 33is configured to protect the respective encapsulated circuit 6, 3 fromink or other fluids. In an example, the encapsulation layer 32, 33includes epoxy.

The example electrical connector pad array 6 of FIG. 4 illustrates firstand second electrical connector pads 7, 8 along two pairs of parallellines 27A, 27B. For example, the layout of the electrical connector padarray 6 is similar or equal to a conventional electrical connector padarray of a conventional flexible circuit of a fluid cartridge. Forexample, each line 27A, 27B has an inclination α, β with respect tosidewall of the flexible substrate 2, for example to facilitate thearrangement of conductor lines 10, 11 towards the first integratedcircuit 3 and the fluid dispensing die 9. As can be seen from FIG. 4lines 27A of a left pair of connector pad sub-arrays have a firstinclination α and lines 27B of a right pair of connector pad sub-arrayshave second inclination β. For example, the inclinations α, β are equalbut in opposite directions.

For example, the first integrated circuit 3 is arranged between theelectrical connector pad array 6 and a side edge of the single flexiblesubstrate 2. For example, this facilitates locating the first integratedcircuit 3 on the front face 26 of the fluid cartridge 80 (FIG. 2). Forexample, this facilitates readily encapsulating the electrical connectorpad array 6 and the first integrated circuit 3. For example, theelectrical connector pad array 6 is symmetrical having an axis ofsymmetry S through the middle of the electrical connector pad array 6,for example between the pairs of the connector pad sub-arrays. Forexample, the axis of symmetry S is arranged next to a center line C ofthe flexible substrate 2. The center line C extends through the centerof the flexible substrate 2, parallel to the longitudinal side edges ofthe flexible substrate 2. In an example, a width W of the flexiblesubstrate 2 is larger than a conventional width of a conventional typeflexible circuit 1 of a similar fluid cartridge 80, for example the sizeof one flexible film's sprocket wider. For example the distance Dbetween the axis of symmetry S of the electrical connector pad array 6and the center line C of the flexible substrate 2 is approximately halfof a sprocket pitch of the flexible film, or a multitude of half of asprocket pitch of the flexible film. For example, the distance D betweenthe center line C and the axis of symmetry S is approximately one,one-and-half, two, two-and-a-half, three, etc. times the sprockets'pitch.

FIG. 6 illustrates a top view of a diagram of an example of the firstintegrated circuit 3. For example the first integrated circuit 3 is asecure microcontroller. In the shown example the first integratedcircuit 3 includes a main integrated circuit 40. Furthermore, at leastfour bond pads 41 are provided that connect the main integrated circuit40 to the conductor lines 10. The bond pads 41 facilitate bonding of theintegrated circuit 40 to the first conductor lines 10. For example, thefirst integrated circuit 3, the bond pads 41 and the first conductorlines 10 are gang bonded together. For example, at the gang bondingstage joints are formed between the conductor lines 10 and the bond pads41. For example, the main integrated circuit 40 and the bond pads 41 arearranged on a relatively rigid substrate 42. For example, anencapsulation layer 32 encapsulates at least the main integrated circuit40 and the bond pads 41. In an example, at least one or at least two ofthe bond pads 41 are connected to combination electrical connector padsA, B (FIG. 2).

In an example, the first integrated circuit 3 includes a securemicrocontroller 50. FIG. 7 illustrates a diagram of an example of asecure microcontroller 50. For example, the secure microcontroller 50includes memory elements connected to an internal bus 51 such as atleast one of a RAM 52, an EEPROM 53, a User ROM 54, and a ST ROM (BootSoftware) 55. For example, the secure microcontroller 50 includes anEDES accelerator 56 connected to the internal bus 51. For example a STROM Firewall 57 is provided between the ST ROM 55 and the internal bus51. For example, the secure microcontroller 50 includes processingmodules that communicate with the internal bus 51, such as at least oneof a Cyclic Redundancy Check (CRC) module 60, a Clock Generator Module61, two times 8-bit timers 62, a Security Monitoring and Control circuit63, a True Random Number Generator 64, an 8/16-bit Central ProcessingUnit Core 65 and an Asynchronous Receiver Transmitter (IART) 66 for highspeed serial data support. For example, further circuits on the securemicrocontroller 50 include a Clock Circuit 70 (CLK), a reset circuit 71,a power supply or Vcc circuit 72, a ground circuit 73, and anInput/Output circuit 74. In an example the Vcc circuit 72 and the groundcircuit 73 are connected to the combination electrical connector pads A,B through conductor lines 10, wherein the combination electricalconnector pads A, B are also connected to the second integrated circuit17. For example, other circuits such as the Clock Circuit 70 or theInput/Output circuit 74 can be unique to the secure microcontroller 50and are not shared with the fluid dispensing die 9.

For example, instead of or in addition to the secure micro controller,the first integrated circuit 3 includes another secure memory.

For example the secure microcontroller 50 is configured to facilitatesecure authentication. For example, in addition to the authenticationcode 29, the secure microcontroller 50 stores further data for exampleincluding at least one of an ink level, reward-related data, coupon orvoucher related data, website addresses, image data, a set ofinstructions for the printer, etc. The secure microcontroller 50 can beco-gang bonded to the flexible substrate 2 together with the fluiddispensing die 9.

FIG. 8 illustrates an example of a method of manufacturing a flexiblecircuit 1 for a fluid dispensing cartridge 80. The example methodincludes providing the constant array 6 of the first and secondelectrical connector pads 7, 8 on a flexible substrate 2 (block 100).For example, the method includes connecting the first integrated circuit3 to the flexible substrate 2 (block 110). For example the firstintegrated circuit 3 is bonded to the flexible substrate 2, for examplegang bonded, for example via first bond pads 41 provided on thesubstrate 2. The first bond pads 41 connect to the first conductor lines10. The example method includes connecting the first integrated circuit3 (or the first bond pads 41) to the first electrical connector pads 7of the array 6 (block 120). For example, the first integrated circuit 3includes a secure microcontroller 50 configured to facilitate secureauthentication of a fluid cartridge 80. The example method includesconnecting the fluid dispensing die 9 to the flexible substrate 2 (block130), at a distance from the first integrated circuit 3. For example thefluid dispensing die 9 is bonded to the flexible substrate 2, forexample gang bonded, for example via bond pads 41 provided on thesubstrate 2, and for example in one step together with the integratedcircuit 3. The second bond pads are connected to the second conductorlines 11. For example, the method includes connecting the secondelectrical connector pads 8 to the fluid dispensing die 9 (block 140),for example to a second integrated circuit 17 thereof. For example, themethod includes attaching the resulting flexible circuit 1 to the fluidcartridge 80 (block 150) so that the fluid dispensing die 9 isfluidically connected to fluid reservoir 12 and the electrical connectorpad array 6 extends on the front face 26.

FIG. 9 illustrates another example of a method of manufacturing aflexible circuit 1 for a fluid dispensing cartridge 80. For example, themethod includes providing the flexible substrate 2, the flexiblesubstrate 2 comprising at least the first window 30 for the firstintegrated circuit 3 and the second window 31 for the fluid dispensingdie 9 and pre-arranged conductor lines 10, 11 (block 200). In anexample, the flexible substrate 2 is pre-manufactured by a third party.For example, the dimensions and locations of the circuits of theflexible circuit 1 are predetermined and determine the dimensions andconfiguration of the flexible substrate 2. For example, the conductorlines 10, 11 are pre-arranged for connecting the die 9 and the firstintegrated circuit 3 to the respective electrical connector pads 7, 8.

For example, the example method of FIG. 9 includes positioning the die 9and the first integrated circuit 3 with respect to the correspondingwindows 30, 31 (block 210), and for example connecting the die 9 and thefirst integrated circuit 3 to the flexible substrate 2 (block 220). Forexample, one or a combination of wire and gang bonding is used toconnect the die 9 and the first integrated circuit 3 to the flexiblesubstrate 2. For example, the method includes gang bonding the firstintegrated circuit 3, the die 9 and the first and second electricalconnector pads 7, 8 to the corresponding conductor lines 10, 11 (block230). For example, one gang bonding tool is used to gang bond therespective connector pads 7, 8 and bond pads 41 to the conductor lines10, 11. The gang bonding process allows for making multiple electricalcontacts in one process step. For example, the electrical connector pads7, 8 and the first integrated circuit 3 are encapsulated using the sameencapsulation material, for example using the same tool, and for examplein the same process step (block 240), for example without moving theflexible substrate 2 with respect to the bond table. In another example,the die 9 and the first integrated circuit 3 are bonded in separateprocess steps, for example the flexible substrate 2 is repositionedafter one of the die 9 or first integrated circuit 3 is bonded. Forexample different bonding tools or tables are used for bonding the die 9and the first integrated circuit 3.

FIG. 10 illustrates another example of a method of manufacturing aflexible circuit 1 for a fluid dispensing cartridge 80. For example, themethod includes writing a cartridge ID 28 on the second integratedcircuit 17 (block 250). For example, the method includes writing anauthentication code 29 corresponding to the cartridge ID 28 on the firstintegrated circuit 3 (block 260). For example, the method includeswriting different cartridge ID 28 s and different correspondingauthentication codes 29 per flexible circuit 1 or per fluid cartridge 80(block 270), so that each fluid cartridge 80 has a unique ID 28 andauthentication code 29. For example, the latter step provides for asecured and unique authentication code 29 per fluid cartridge 80.

For example, some of the features disclosed in this specificationprovide for the ability to securely authenticate a flexible circuit 1 orfluid cartridge 80, while allowing for an integrated and cost efficientmanufacturing thereof. For example, the integrated circuit 3 isconfigured to facilitate secure authentication. In different examples,different host devices are able to authenticate the flexible circuit 1or fluid cartridge 80, for example a printer, smart phone, a web server,any computing device, etc. In an example the host device interfaces withthe flexible circuit 1 through the printer. In an example, the firstintegrated circuit 3 is configured to store further data such as fluidrelated codes, color adjustment information, voucher related codes,advertisements, coupons, etc. For example, the host device can access,modify or process such further data only after the secure authenticationhas been established through the first integrated circuit 3. Forexample, the first integrated circuit 3 is configured to provide, orprovide access to, above mentioned further data only after theauthentication is established. In an example, the fluid dispensing die 9needs little or no adaptations with respect to existing integratedprintheads. In another example, the flexible substrate 2 and electricalconnector pad array 6 need little or no adaptations with respect toexisting electrical connector pad arrays of integrated printhead fluidcartridges. For example, the integrated circuit 3 is gang bonded toconductor lines 10 at the same time as the fluid dispensing die 9, at adistance from the fluid dispensing die 9, and to the same flexiblesubstrate 2.

For example, the flexibility of the flexible circuit 1 refers to theflexible substrate 2 while some of the circuits on the flexiblesubstrate 2 may in itself be relatively rigid. In fact, in an examplethe flexible circuit 1 can be relatively rigid due to the circuits onthe flexible substrate 2. For example, in addition to or instead of gangbonding, wire bonding or other suitable welding methods can be used, forexample including the use of heating processes, electrical energy orchemical components.

In one example, the fluid cartridge 80 is adapted to be connected to ahost device. In another example, the fluid cartridge 80 is part of ahandheld fluid dispensing device. In yet another example, the fluiddispensing device or host device is a printer or titration device oranother type of high precision fluid dispensing device.

The above description is not intended to be exhaustive or to limit thisdisclosure to the examples disclosed. Other variations to the disclosedexamples can be understood and effected by those of ordinary skill inthe art from a study of the drawings, the disclosure, and the claims.The indefinite article “a” or “an” does not exclude a plurality, while areference to a certain number of elements does not exclude thepossibility of having more or less elements. A single unit may fulfilthe functions of several items recited in the disclosure, and vice versaseveral items may fulfil the function of one unit. Multiplealternatives, equivalents, variations and combinations may be madewithout departing from the scope of this disclosure.

What is claimed is:
 1. A flexible circuit for a fluid cartridge,comprising a single flexible substrate; an integrated circuit connectedto the single flexible substrate; and an electrical connector pad arrayarranged in a constant pattern on the single flexible substrate forconnection to a host controller, the electrical connector pad arrayincluding first electrical connector pads connected to the integratedcircuit and second electrical connector pads for connection to a fluiddispensing die.
 2. The flexible circuit of claim 1, wherein theintegrated circuit includes a secure microcontroller.
 3. The flexiblecircuit of claim 1, wherein at least a portion of the first and thesecond electrical connector pads are arranged on one straight line. 4.The flexible circuit of claim 1, wherein: the integrated circuit isarranged between the electrical connector pad array and a side edge ofthe single flexible substrate; and an axis of symmetry of the electricalconnector pad array is arranged parallel to and at a distance from alongitudinal center line of the flexible substrate.
 5. The flexiblecircuit of claim 1, comprising the fluid dispensing die and wherein theelectrical connector pad array includes at least one electricalconnector pad that is connected to both the integrated circuit and thefluid dispensing die.
 6. The flexible circuit of claim 1, wherein thefirst electrical connector pads include at least four first electricalconnector pads.
 7. The flexible circuit of claim 1 comprising: bond padsfor connecting the integrated circuit to a conductor line connected tothe electrical connector pads; and an encapsulation layer covering theintegrated circuit, the bond pads, and the electrical connector padarray.
 8. The flexible circuit of claim 1, comprising the fluiddispensing die and wherein: the single flexible substrate includes afirst window and a second window; the integrated circuit is connected tothe flexible substrate near edges of the first window; and the fluiddispensing die is connected to the flexible substrate near edges of thesecond window.
 9. A fluid cartridge, comprising a fluid reservoir; afluid dispensing die; a single flexible substrate; a first integratedcircuit connected to the single flexible substrate; an electricalconnector pad array arranged in a constant pattern on the singleflexible substrate for connection to a host controller, the electricalconnector pad array including first electrical connector pads connectedto the integrated circuit and second electrical connector pads connectedto the fluid dispensing die; a second integrated circuit connected to atleast one of the second electrical connector pads, distanced from thefirst integrated circuit, connected to the fluid dispensing die, andconfigured to signal actuators in the fluid dispensing die; a cartridgeID stored on the second integrated circuit; and an authentication codestored on the first integrated circuit, the authentication codecorresponding to the cartridge ID so that the cartridge ID and theauthentication code can be matched by the host controller.
 10. Fluiddispensing cartridge comprising a flexible substrate; an integratedcircuit connected to the flexible substrate; a fluid dispensing dieconnected to the same flexible substrate as the integrated circuit; anda constant electrical connector pad array arranged on the same flexiblesubstrate as the integrated circuit and the fluid dispensing die, forconnection to a host controller, the electrical connector pad arrayincluding first electrical connector pads connected to the integratedcircuit and second electrical connector pads connected to actuators inthe fluid dispensing die
 11. A method of manufacturing a flexiblecircuit for a fluid dispensing cartridge, comprising providing aconstant array of first and second electrical connector pads on aflexible substrate; connecting an integrated circuit to the flexiblesubstrate; connecting a fluid dispensing die to the flexible substrate;connecting the integrated circuit to the first electrical connectorpads; and connecting the fluid dispensing die to the second electricalconnector pads.
 12. The method of claim 11, comprising: positioning thefluid dispensing die and the integrated circuit with respect tocorresponding windows in the flexible substrate; and wherein connectingthe integrated circuit to the first electrical connector pads includesgang bonding the integrated circuit to first conductor lines on theflexible substrate; and connecting the fluid dispensing die to thesecond electrical connector pads includes gang boding the fluiddispensing die to second conductor lines on the flexible substrate inthe same process step with gang bonding the integrated circuit to thefirst conductor lines.
 13. The method of claim 12, comprisingencapsulating the electrical connector pads and the integrated circuitwith the same material using the same encapsulation tool.
 14. The methodof claim 11, wherein the integrated circuit includes a securemicrocontroller.
 15. The method of claim 11, comprising: writing acartridge ID on the fluid dispensing die; and writing an authenticationcode on the integrated circuit, the authentication code corresponding tothe cartridge ID on the fluid dispensing die.